Zute, first some comments on apparent misconceptions that you mention. If your Pioneer has a rated 110 watts/channel, you'll get at least that much "real" power since it would be against the law(FTC regulations)to use that rating otherwise.

As already mentioned, never use the lower impedance setting, since all it does it to reduce the voltage output and as a result, the maximum power capability.

You can't "bi-amp" with a receiver, despite any advertising claim to the contrary. The receiver has just one amplifier with one main power supply section, and this capacity can't be increased in any amount by adding extra wire connections.

Your Pioneer should have no problem in driving an M80/VP180 front line at all levels which won't endanger your hearing. The side surrounds should remain your QS8s. For back surrounds in a 7.0 setup another pair of QS8s would certainly be appropriate, but if you have enough room behind your listening position(say at least 6')for their sound to spread out, M2s would also be suitable back there.

Thanks for the info JohnK. I'm always learning something new here. Since my room is 20' deep I'm about 12' to 14' from the front leaving me ample room behind. So going with some M2 or 3's would work. Not that I'm totally against QS8's just trying to weigh my options.

If I do go with the small bookshelfs I assume I would mount them close to ear level. I know the QS8's are mounted above but with my current setup everything is ear level except the 8's.

And as you and others have pointed out my receiver should be fine and if it ain't I'll get something better suited.

My configuration is M22 fronts, VP150 center, QS8 side surrounds, and M2 rears with an SVS PC13 sub all driven by a pioneer VSX-45. I listen to stereo source material in 7 channel stereo mode and it sounds fine to me.

If I had to do without a sub I would want M80 fronts for their lower end capability, and the VP180 if I could rationalize the expense. I wouldn't change the sides or rears because I don't think there would be significant difference. Just my opinion of course.

The only change I'd consider in your upgrade comment is using M3's instead of M2's for the rears. I believe they are a better match for the M80's...I think I read that here sometime ago - they may have been talking about the M60's instead, don't remember...getting to old to trust my memory!

The M80 and the M22 produce a much flatter response than the M60 and the M3. The M3 has a slight bass hump, and the M60 has 1 less tweeter and mid-range woofer. So, it looks to me that the M3 would be a better match with the M60.

You're right, I forgot about the M50. But their still has to be some sonic difference in the M60 with fewer high end speakers that would cause it to be a better match with M3 than the M80. That's all I was thinking.

My real concern is timber matching all speakers for best sound. I know the VP180 plays well with the M80's but which of the bookshelfs are best suited in this combination?

IMO the M80s, M22s, M2s and QS8s are as perfect a sonic match as you will find with any system of speakers. I can’t comment on other Axiom offerings since I haven’t heard them but based on the driver complement and comments from other assume that the VP180 is also a perfect match.

My room is 21 feet deep with the front of my M80s 4 feet off the front wall and my seating 12 feet from the mains, about 11.5 from the center which give me about 5-6 feet behind me. I’ve tried M22s, M2s and QS8s as rear speakers in this room and found no difference between the M22s and M2s. IMO the QS8s are marginally better as rears even at 5 feet because the way the spread out the sound helps them blend better with the QS8 surrounds. So if money is no object I would go with QS8 rears, however if you want to switch out to bookshelf rears I’d go with M2s.